1. Field of the Invention
This invention relates to a material to stabilize waste and a method of producing the material, and more specifically, this invention relates to a ceramic material to stabilize low-level mixed wastes and a method for producing the ceramic material.
2. Background of the Invention
Low-level mixed wastes contain hazardous chemical and low-level radioactive materials. Generally, mixed waste streams contain aqueous liquids, heterogeneous debris, inorganic sludges and particulates, organic liquids and soils. The projected volume over the next five years of the mixed waste generated by the U.S. Department of Energy alone is estimated at approximately 1.2 million cubic meters.
Stabilization of these mixed wastes requires that both phases of contaminants are stabilized effectively.
Typical approaches to stabilization and storage of these mixed wastes include vitrification. For example, one process (Crowe, U.S. Pat. No. 5,302,565) requires firing temperatures of at least 1850.degree. C. for at least 12 hours to produce ceramic containers. However, such processes, associated with high temperatures are costly. In addition, vitrification of waste streams often result in the lighting off of volatile components which often are contained in the waste stream. This lighting off results in the unwanted generation of secondary waste streams.
One system for producing cements having ceramic type properties, does not require high temperatures for final crystallization (Sugama et al. U.S. Pat. No. 4,436,555, assigned to the instant assignee). However, that process results in ammonia being liberated during processing and storage, which leads to container corrosion.
A need exists in the art for a low level waste encapsulation technology that connotes relatively high strength and low porosity to the final product, and which also sets up at low temperatures. The final product must exhibit low leachability and high durability in aqueous systems.